21214035651217 has 2 divisors, whose sum is σ = 21214035651218. Its totient is φ = 21214035651216.

The previous prime is 21214035651103. The next prime is 21214035651233. The reversal of 21214035651217 is 71215653041212.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19186931723521 + 2027103927696 = 4380289^2 + 1423764^2 .

It is a cyclic number.

It is not a de Polignac number, because 21214035651217 - 2²³ = 21214027262609 is a prime.

It is a super-2 number, since 2×21214035651217² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21214035651217.

It is not a weakly prime, because it can be changed into another prime (21214035651517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10607017825608 + 10607017825609.

It is an arithmetic number, because the mean of its divisors is an integer number (10607017825609).

Almost surely, 2^{21214035651217} is an apocalyptic number.

It is an amenable number.

21214035651217 is a deficient number, since it is larger than the sum of its proper divisors (1).

21214035651217 is an equidigital number, since it uses as much as digits as its factorization.

21214035651217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 100800, while the sum is 40.

Adding to 21214035651217 its reverse (71215653041212), we get a palindrome (92429688692429).

The spelling of 21214035651217 in words is "twenty-one trillion, two hundred fourteen billion, thirty-five million, six hundred fifty-one thousand, two hundred seventeen".